Comparison of the distribution of the Bartholin and/or Rivinus salivary ducts assessed with magnetic resonance-sialography in patients with ranula and in healthy subjects.

Background: The distribution and drainage of the sublingual gland ducts have various patterns that might be related to sublingual gland-related diseases, including ranula. This study aimed to elucidate the characteristics of the distribution of Bartholin and/or Rivinus ducts in patients with ranula using magnetic resonance (MR) sialography. Methods: In this retrospective cross-sectional study, the distributions and drainage patterns of sublingual gland ducts on MR sialography were classified in 74 subjects without sublingual gland-related disease as confirmed by both medical history and clinical examination and 15 patients with ranula, respectively. All patients had visited Kyushu Dental University Hospital from July 2015 to June 2022 to undergo MR imaging. Data on the distributions and drainage patterns of the sublingual gland ducts, including the characteristics of the Bartholin and/or Rivinus ducts, were then statistically compared between subjects without sublingual gland-related disease and patients with ranula. The images were assessed by an experienced oral and maxillofacial radiology specialist certified by the Japanese Society for Oral and Maxillofacial Radiology. The distributions (five groups) and drainage patterns (three patterns) of the sublingual gland ducts on MR sialography were classified in reference to previous studies, with some modifications in all subjects without sublingual gland-related disease and patients with ranula. Results: A significant difference in the distribution of the ducts (P<0.001), with a low number of patients exposing an undetected canal or Rivinius duct, was found in the group of patients with ranula (P<0.05). Regarding drainage patterns, no patient with ranula presented a Rivinius duct only. A significant difference in the drainage patterns of the sublingual gland ducts on MR sialography was observed between subjects without sublingual gland-related disease and patients with ranula (P=0.001). Conclusions: The present results suggest that the distribution of the sublingual gland ducts, mainly, the Bartholin duct, may be related to ranula formation. These findings also demonstrate that MR sialography contributes well to preoperative evaluation and is effective for assessing the complex excretory distribution of the sublingual gland ducts.

Physiological role of the EHL gene in sake yeast and its effects on quality of sake.

The EHL1/2/3 genes were identified by whole-genome sequencing of Kyokai No. 7 (K7), which is a well-known representative Japanese sake yeast Saccharomyces cerevisiae. The genes are present in K7, but not in laboratory strain S288C. Although the genes were presumed to encode epoxide hydrolase based on homology analysis, their effect on cellular metabolism in sake yeast has not yet been clarified. We constructed ehl1/2/3 mutants harboring a stop codon in each gene using the haploid yeast strain H3 as the parental strain, which was derived from K701, and investigated the physiological role and effects of the EHL1/2/3 genes on sake quality. Metabolome analysis and vitamin requirement testing revealed that the EHL1/2/3 genes are partly responsible for the synthesis of pantothenate. For fermentation profiles, ethanol production by the ehl1/2/3 mutant was comparable with that of strain H3, but succinate production was decreased in the ehl1/2/3 mutant compared to strain H3 when cultured in yeast malt (YM) medium containing 10% glucose and during sake brewing. Ethyl hexanoate and isoamyl acetate levels in the ehl1/2/3 mutant strain were decreased compared to those of strain H3 during sake brewing. Thus, the EHL1/2/3 genes did not affect ethanol production but did affect the production of organic acids and aromatic components during sake brewing.

The bio3 mutation in sake yeast leads to changes in organic acid profiles and ester levels but not ethanol production.

Biotin is an essential coenzyme that is bound to carboxylases and participates in fatty acid synthesis. The fact that sake yeast exhibit biotin prototrophy while almost all other Saccharomyces cerevisiae strains exhibit biotin auxotrophy, implies that biotin prototrophy is an important factor in sake brewing. In this study, we inserted a stop codon into the biotin biosynthetic BIO3 gene (cording for 7,8-diamino-pelargonic acid aminotransferase) of a haploid sake yeast strain using the marker-removable plasmid pAUR135 and investigated the fermentation profile of the resulting bio3 mutant. Ethanol production was not altered when the bio3 mutant was cultured in Yeast Malt (YM) medium containing 10% glucose at 15 °C and 30 °C. Interestingly, ethanol production was also not changed during the sake brewing process. On the other hand, the levels of organic acids in the bio3 mutant were altered after culturing in YM medium and during sake brewing. In addition, ethyl hexanoate and isoamyl acetate levels decreased in the bio3 mutant during sake brewing. Metabolome analysis revealed that the decreased levels of fatty acids in the bio3 mutant were attributed to the decreased levels of ethyl hexanoate. Further, the transcription level of genes related to the synthesis of ethyl hexanoate and isoamyl acetate were significantly reduced. The findings indicated that although the decrease in biotin biosynthesis did not affect ethanol production, it did affect the synthesis of components such as organic acids and aromatic compounds. Biotin biosynthesis ability is thus a key factor in sake brewing.

Analysis of external nasal morphology and the direction of maxillary repositioning following Le Fort I osteotomy.

This study investigated the relationship between the direction of maxillary repositioning after Le Fort I osteotomy and changes in external nasal morphology using lateral cephalograms and frontal facial photographs. The results indicated greater changes in external nasal morphology, such as a more forward position of the nasal tip and an increased alar base width, with anterosuperior repositioning than with posterosuperior repositioning. In conclusion, this study demonstrated that the external nasal morphology changes after Le Fort I osteotomy, and that the changes vary depending on the direction of maxilla repositioning.

Elucidation of the enzyme involved in 2,3,5-triphenyl tetrazolium chloride (TTC) staining activity and the relationship between TTC staining activity and fermentation profiles in Saccharomyces cerevisiae.

2,3,5-Triphenyl tetrazolium chloride (TTC) staining is a method to distinguish the mitochondrial activity of cells based on the color: colorless TTC turns red when under reducing conditions. Although the assay reflects the mitochondrial activity of cells, which enzyme(s) in the electron transport system contribute to TTC reduction has been unclear. TTC staining assays using gene disruptants related to the electron transport system in Saccharomyces cerevisiae revealed those disruptants related to electron transport from each electron donor to ubiquinone (red colonies) and disruptants that were related to ubiquinol-cytochrome c oxidoreductase and cytochrome c oxidase (white colonies). In addition, when the enzyme activities of ubiquinol-cytochrome c oxidoreductase and cytochrome c oxidase were measured using TTC as the electron acceptor, only ubiquinol-cytochrome c oxidoreductase showed TTC reduction activity, and the activity was enhanced by potassium cyanide, an inhibitor of cytochrome c oxidase. These results indicated that ubiquinol-cytochrome c oxidoreductase is involved in TTC reduction in S. cerevisiae. The fermentation profiles of BY4741UΔcor1 and BY4741UΔcox4, which exhibited no TTC staining activity, were almost identical to that of the parental strain BY4741U. However, cell growth and ethanol and succinate production of the ura3-mutated strain BY4741, which also exhibited no TTC staining activity, was altered compared to those of BY4741U, indicating that the fermentation profile varies among strains that show no TTC staining activity. The relationship between uracil metabolism and TTC staining activity was also determined based on metabolome analysis.